CN102905831A

CN102905831A - A method for the manufacture of a wear pad for a band saw blade guide, such a wear pad, and the use of a steel material for producing the wear pad

Info

Publication number: CN102905831A
Application number: CN2011800247738A
Authority: CN
Inventors: J.博斯特罗姆
Original assignee: Uddeholms AB
Current assignee: Uddeholms AB
Priority date: 2010-03-17
Filing date: 2011-03-09
Publication date: 2013-01-30
Also published as: RU2012139083A; SE1050244A1; KR20130004504A; CA2792962A1; SE535090C2; WO2011115547A1; US20130052075A1; BR112012023896A2; JP2013522470A; TW201143940A; EP2547478A1

Abstract

A wear pad of a band saw guide exposed to wear from a moving band saw blade is produced in a powder metallurgical manner from a steel material having the following composition (1), in per cent by weight: and, further, 7.5 to 14 of (V + Nb/2), wherein the contents of N, on one hand, and of (V + Nb/2), the other hand, are balanced in relation to each other so that the contents of said elements are within an range I", F", G, H, I" in a perpendicular, plane coordinate system, where the content of N is the abscissa and the content of V + Nb/2 is the ordinate, and where the coordinates (2), for said points are: and max 7 of any of Ti, Zr, and A1; balance essentially only iron and unavoidable impurities.

Description

For the preparation of the method for the pad abrasive disc of bands for band guider, such pad abrasive disc, and steel are for the preparation of the purposes of described pad abrasive disc

Technical field

The present invention relates to the method for the preparation of the pad abrasive disc (wear pad) of bands for band guider (band saw blade guide), described pad abrasive disc is exposed to the wearing and tearing of mobile bands for band.

The invention still further relates to the pad abrasive disc of bands for band guider, described pad abrasive disc is exposed to the wearing and tearing of mobile bands for band.

In addition, the present invention relates to steel and be used for the purposes that powder metallurgy prepares the pad abrasive disc of bands for band guider, described pad abrasive disc is exposed to the wearing and tearing of mobile bands for band.

Background technology

The feature of band saw is the combination of band saw motor and bands for band usually, it is by operating so that can be with certain track or pliable and tough, the continuous zigzag bands for band of path drives, be used for the cutting multiple material, comprise timber, stock (wood stock), metal, pottery and plastics.Because it is dilatory that bands for band centers on the bands for band driving wheel that separates on a pair of space usually, the cutting planes of Orbiting bands for band will be vertical plane or horizontal plane, and cutting part level or the vertical-path by move of a kind of mechanism with guiding belt saw blade must be provided.In addition, because bands for band is thin with pliable and tough, so it stands a large amount of vibrations and distortion in the process of sawing operation, like this, if bands for band can not sufficient stabilization on level or perpendicular cuts plane, then may cause the inhomogeneous cutting in the workbench (work stock).Accordingly, bands for band guiding or stabiliser are the known means in band saw field.

Such bands for band guiding mechanism is disclosed in US 3,534, in 647, and comprises a pair of supporting arm, and this supporting arm extends between a pair of drive pulley that vertically separates, and arranges continuous bands for band on it.The bands for band guider assembly that is placed in each supporting arm extended end is accepted bands for band, and carbide insert (carbide inserts) is matched with in the bands for band guider assembly, with the contact zones saw blade to side surface and make the minimum vibration of the bands for band cutting part between the bands for band guider assembly, because bands for band drives in drive pulley.

Usually, carbide is sintered-carbide (cemented carbide), is also referred to as tungsten-carbide cobalt or hard metal, and it is a kind of metal matrix composite, and wherein tungsten carbide particle is aggregation, and metallic cobalt is as matrix.Between many decades, sintered-carbide has been used for instead of steel in the unsafty application of the performance of steel, and the sintered-carbide piece is connected to suitable substrate by brazing.Subject matter with the pad abrasive disc of sintered-carbide piece is its life-span, and its life-span is owing to sintered-carbide breaks and broken the termination.In addition, the pad abrasive disc with sintered-carbide piece (blocks) involves great expense.

US 6,889, and 589B1 and US 7,325,473B2 disclose the guider that is used for the saw blade of stable saw milling cutter assembly (saw millassembly).Described guider comprises guide block, and it has first surface and relative second surface for the surface that engages saw blade.Guide block or insert are bimetallic, are stiffer than the metal material that is adjacent to the second guider-mating surface so that be adjacent to the metal material of its first bands for band-mating surface.Described harder material is preferably austenite chromium-carbide alloy, and its Brinell hardness number is 460 to 614.

In addition, WO 2007/024192A 1 (Uddeholm Tooling Aktiebolag) discloses a kind of steel alloy of powder metallurgy preparation and instrument and the assembly that alloy is made.Described alloy has the composition of following % by weight: 0.01 to 2 C, 0.6 the N to 10,0.01 the Si to 3.0,0.01 the Mn to 10.0,16 to 30 Cr, 0.01 the Ni to 5,0.01 to 5.0 (Mo+W/2), 0.01 to 9 Co, be 0.5 S to the maximum, with 0.5 to 14 (V+Nb/2), wherein on the one hand the content of N and the on the other hand content of (V+Nb/2) relative to each other carry out balance, so that the content of these elements is by coordinate A ', B ', G, H, A ' limits, wherein [N, (V+Nb/2)]-coordinate is for these points: A ': [0.6,0.5]; B ': [1.6,0.5]; G:[9.8,14.0]; H:[2.6,14.0], and among Ti, Zr and the Al any be 7 to the maximum, and surplus only is the impurity of iron and normal contents basically.Steel is intended to injection moulding, the pressure molding for the preparation of plastic assembly and extrudes used instrument, and the cold work tool of experience corrosion.In addition, also be used for the engineering assembly, machine injection nozzle for example, antifriction metal (AFM) assembly, pump assembly, bearing assembly etc.The Another Application field is that steel alloy is for the preparation of the purposes of food industry with cutter.WO2007/024192A1 integral body is incorporated herein and is for referencial use.

Summary of the invention

An object of the present invention is to provide the method for the pad abrasive disc of preparation bands for band guider, described pad abrasive disc has the longer life-span and lower than the pad abrasive disc cost of using sintered-carbide.

In the described method of above-mentioned first paragraph, this purpose is achieved by the invention consistent with the claim of enclosing.

The steel pad abrasive disc that more than forms has the significantly longer life-span, is more than the twice in the pad abrasive disc life-span of using sintered-carbide.In addition, it is significantly more cheap, namely is about half of cost of the pad abrasive disc that uses sintered-carbide.The most important thing is, the significant advantage of pad abrasive disc of the present invention is that it does not break or broken (chip), thus owing to make band saw eliminate the situation of unexpected breakage (this is to use the pad abrasive disc the present and the future of sintered-carbide all can occur) so that availability increase.Therefore, can predict easily the situation that any needs change pad, the maintenance work that therefore is easy to plan with other types is carried out.In addition, it the time can grind in wearing and tearing, then can within another military service cycle, reuse, and break or broken sintered-carbide piece must from substrate remove and with new piece brazing in substrate.In addition, the steel pad abrasive disc that more than forms is useful to environment, because its noise level descends, this has reduced again the vibration in the bands for band, and thereby may improve the band saw service life of a machine.Generally speaking, the present invention provides surprising synergy significantly.

Except the above-mentioned advantage relevant with the inventive method, the high-abrasive material of above-mentioned composition is balance about the relative content of vanadium of nitrogen content and the niobium that may exist in preferred embodiment.This microscopic structure has stone, the stable hard-phase particles of high-load, and its wear surface can satisfy the high request of anti-stick button (anti-galling) and anti-fretting (anti-fretting) character easily simultaneously, because it has extraordinary corrosion resistant character, according to claim 8.

Another object of the present invention provides steel and is used for the purposes that powder metallurgy prepares the pad abrasive disc of bands for band guider, described pad abrasive disc is exposed to the wearing and tearing of mobile bands for band, this pad abrasive disc has than the longer life-span of pad abrasive disc of using sintered-carbide, according to claim 10.

Thus, may use the steel of described powder metallurgy preparation to be used for the underlay abrasive disc, this pad abrasive disc needs extraordinary wearability at the product surf zone, and this product preferably satisfies following the requirement simultaneously: corrosion resistance, machinability, ductility, machinability (machinability), hardness, for the heat treatment response of substrate and wearing layer.

Other characteristics of different embodiments of the present invention and by these embodiments and resulting benefit will become obvious by following detailed description and claim.

Description of drawings

Below, the present invention will preferred embodiment describe with accompanying drawing in more detail by reference.

Fig. 1 shows the ratio of the N content of used steel and content (V+Nb/2), with the coordinate system form,

Fig. 2 is the figure that shows wearability,

Fig. 3 is the figure that shows corrosion resistance,

Fig. 4 shows that described steel carry out high temperature insostatic pressing (HIP) according to the preferred embodiment of the present invention by the microscopic structure of the wearing layer of the steel preparation of powder metallurgy preparation, then heat treatment,

Fig. 5 is the figure that shows the frictional property of Vanax 75,

Fig. 6 is the figure that shows the frictional property of Vanax 75,

Fig. 7 is the comparison diagram of the relative temperature of hardness between wear-resisting steel of the present invention,

Fig. 8 is the side view of an embodiment preferred embodiment of pad abrasive disc of the present invention, and this pad abrasive disc is used for the bands for band guider and is exposed under the wearing and tearing of mobile bands for band,

Fig. 9 is the plane of the pad abrasive disc of Fig. 8, and

Figure 10 is the sectional view that the XV – XV line along Fig. 9 obtains.

Detailed description preferred embodiment

Steel

The used steel of pad abrasive disc of the present invention prepare by powder metallurgy, and this condition is not so that described steel has oxide to mix to a great extent, and obtain following microscopic structure, and this microscopic structure comprises the equally distributed at the most M of 50 volume % ₂X-, MX-and/or M ₂₃C ₆/ M ₇C ₃The hard-phase particles of type, described particle are of a size of 1 to 10 μ m in its longest elongation, the content of wherein said hard-phase particles distributes like this: 20 volume % are M at the most ₂The X-carbide ,-nitride and/or-carbonitride, wherein M is mainly V and Cr, and X is mainly N, and 5 to 40 volume % be the MX-carbide ,-nitride and/or-carbonitride, wherein M is mainly V, and X is mainly N, and the average-size of wherein said MX-particle is lower than 3 μ m, preferably be lower than 2 μ m, and even more preferably less than 1 μ m.Preferably, described powder metallurgy preparation comprises the gas atomization of steel melt, adopts nitrogen as atomization gas, and it gives the nitrogen of the certain minimum content of described steel alloy.By the solid phase nitriding of powder, can obtain the higher nitrogen content of wanting.

Below be effective for the alloying element of described steel.

At first, carbon should be present in the amount of abundance in the steel of the present invention, to impel steel to be issued to high rigidity up to 60 to 62HRC in its sclerosis and tempered condition with nitrogen in the solid solution of steel matrix.With nitrogen, carbon also can be present in the M of primary precipitated ₂The X-nitride ,-carbide and/or-carbonitride in, wherein M is mainly V and Cr, and X is mainly N, and be present in primary precipitated the MX-nitride ,-carbide and/or-carbonitride in, wherein M is mainly V, and X is mainly N, and is present in the M that may exist ₂₃C ₆-and/or M ₇C ₃In-the carbide.

Carbon should give required hardness with nitrogen, and forms the hard phase that is contained in the steel.The content of carbon in the steel, namely the carbon in the solid solution in the steel matrix adds the carbon of combination in carbide and/or carbonitride, the reason that should remain on because of preparation economic cause and phase has the low-level of motivation employing.Steel should be able to also can be converted into martensite by austenitizing when sclerosis.When needing, depth of material is freezing, to avoid retained austenite.Preferably, carbon content should be at least 0.01%, even more preferably at least 0.05%, and most preferably at least 0.1%.Greatest carbon content can allow to be to the maximum 2%.Depend on application, carbon content at first is adapted to form in the content of nitrogen in steel and the steel total content of elemental vanadium, molybdenum and the chromium of carbide, so that the M of steel ₂The X-carbide ,-nitride and/or-content of carbonitride 20 volume % at the most, and the MX-carbide ,-nitride and/or-content of carbonitride is 5 to 40 volume %.M ₂₃C ₆-and/or M ₇C ₃-carbide can exist with the content up to 8 to 10 % by weight, mainly is very high chromium content.Yet the MX-in the steel, M ₂X-and/or M ₂₃C ₆/ M ₇C ₃-carbide ,-nitride and/or-the carbonitride total content should be no more than 50 volume %.In addition, the existence of other carbide should minimize in the steel, so that the content of the chromium that dissolves in the austenite is not less than 12%.Preferably, the content of dissolve chromium is at least 13% in the austenite, and even more preferably at least 16%, it guarantees that steel obtains good corrosion resistance.

Nitrogen is alloying element necessary in the steel of the present invention.As carbon, nitrogen should be present in the solid solution of steel matrix, to give the sufficient hardness of steel and to form required hard phase.Preferably, nitrogen is used as atomization gas in the powder metallurgy preparation technology of metal dust.Utilize such powder preparation, steel will contain and be 0.2 to 0.3% nitrogen to the maximum.Then give this metal dust required nitrogen content according to known technology, described technology for example makes the powder of producing pressurize in nitrogen or the solid phase nitriding, and therefore described steel contains at least 1.6% aptly, preferred at least 2.6% nitrogen.Owing to use pressurization or solid phase nitriding in the nitrogen, certainly also might allow this another atomization gas of atomizing use for example argon gas carry out.

In order not cause the fragility problem and to obtain retained austenite, the nitrogen content maximization is to 9.8%, preferred 8%, and even more preferably be 6% to the maximum.Because vanadium and other strong nitride/carbide formations (for example chromium and molybdenum) have the trend with nitrogen and carbon reaction, carbon content should be adapted to high nitrogen content simultaneously, so that the carbon content maximization is 1.5% to the maximum aptly to 2% for above-mentioned nitrogen content, preferably be 1.2% to the maximum.Yet in this, should notice that corrosion resistance descends along with the increase of carbon content, and anti-stick button (galling resistance) property will descend, this is disadvantageous, especially because can the relatively large chromium carbide of formation than steel of the present invention (its carbon content be lower than above-mentioned high-load), M ₂₃C ₆And/or M ₇C ₃

Have at steel in the situation of enough lower nitrogen content, therefore also need to reduce carbon content.Preferably, carbon content is limited to because of economic cause low-level that motivation adopts, but according to the present invention, carbon content can change in certain nitrogen content situation, wherein can make the content of hard-phase particles in the steel and its hardness expect that according to described steel the field of using changes.At some content of corrosion inhibition alloying element chromium and molybdenum, nitrogen also helps lend some impetus to the formation of MX-carbonitride, and helps to suppress M ₂₃C ₆And/or M ₇C ₃Formation, described M ₂₃C ₆And/or M ₇C ₃Reduce the corrosion resistance of steel in disadvantageous mode.

Silicon is as the residue of steel production and exist, and minimum content can be 0.01%.When high content, silicon has given the solution hardening effect, but has also given certain fragility.Silicon or a kind of stronger ferrite formation, and therefore cannot exist with the amount above 3.0%.Preferably, described steel does not contain the silicon more than maximum 1.0%, is aptly 0.8% to the maximum.Specified silicone content is 0.3%.

Manganese helps to give the good hardenability of steel (hardenability).For avoiding the fragility problem, manganese cannot exist with the amount above 10.0%.Preferably, described steel does not contain the manganese more than maximum 5.0%, is aptly 2.0% manganese to the maximum.In the unimportant embodiment of hardenability, manganese is present in the steel with low content as the residual elements of steel production, and with can be by forming manganese sulfide in conjunction with a certain amount of sulphur that can exist.Therefore manganese should exist with at least 0.01% content, and the scope of suitable manganese is 0.2 to 0.4%.

Chromium should with 16%, preferred 17% and even more preferably at least 18% minimum content exist, to give steel required corrosion resistance.Chromium also is a kind of important nitride formation, and should with nitrogen, give steel a certain amount of hard-phase particles as a kind of element that exists in the steel, and this helps to give steel required anti-stick button and wearability.In the described hard-phase particles, 20 volume % can be by M at the most ₂The X-carbide ,-nitride and/or-carbonitride forms, wherein M is mainly Cr but also can be a certain amount of V, Mo and Fe, and 5 to 40% can by the MX-carbide ,-nitride and/or-carbonitride forms, wherein M is mainly V.Yet chromium is a kind of strong ferrite formation.Be the ferrite after avoiding hardening, chromium content must not surpass 33%, and its amount is 30% to the maximum aptly, preferably is 27% to the maximum, and even more preferably is 25% to the maximum.

Nickel is optional element, and may be as the austenite stable element to be 5.0% and be aptly 3.0% content to the maximum and exist to the maximum, with the ferrite former chromium in the balance steel and the high-load of molybdenum.Yet steel of the present invention preferably contains the nickel of involuntary addition.Yet nickel can be used as inevitable impurity and is tolerated that its content may be up to about 0.8% thus.

Cobalt also is the element of choosing wantonly, and may be to be 9% and be aptly 5% content to the maximum and exist to the maximum, to improve the tempering response.

Molybdenum should be present in the steel, because it helps to give steel required corrosion resistance, and particularly good anti-fretting.Yet molybdenum is a kind of strong ferrite formation, and therefore must not contain more than maximum 5.0% in the steel, is aptly 4.0% to the maximum, preferably is 3.5% Mo to the maximum.Specified molybdenum content is 1.3%.

Molybdenum can completely or partially be substituted by tungsten in principle, yet tungsten does not give the identical improvement of corrosion resistance.In addition, need to double the tungsten of molybdenum, this is disadvantageous.In addition, old metal is processed also more difficult.

The content that vanadium is present in the steel should be 7.5 to 11.0%, and is preferred 8.5 to 10.0%, and even more preferably 8.8 to 9.2%.Specified content of vanadium is 9.0%.In the scope of the inventive concept, also conceivable is to allow content of vanadium up to about 14%, and nitrogen content is up to about 9.8%, and the carbon content scope is 0.1 to 2%, it gives steel required character, the purposes of hard material coating in the instrument, described coating have the corrosion resistance of high request and high rigidity (up to 60 to 62HRC) and moderate ductility and the wearability (abrasive wear (abrasive)/bonding wearing and tearing (adhesive galling)/fretting) of high requirement.

In principle, vanadium can by niobium substitute to form the MX-nitride ,-carbide and/or-carbonitride, but need in this case the amount larger than vanadium, this is disadvantageous.In addition, niobium makes nitride, carbide and/or carbonitride obtain that the shape (edged shape) on limit is more arranged and greater than pure vanadium nitride, carbide and/or carbonitride, and this may cause and breaks or broken and therefore reduce toughness and the polishability of material.This can be special harmful (about the engineering properties of material) for steel when composition being optimized reach the combination of excellent wearability and good ductility and high rigidity.In this case, described steel must not contain more than maximum 2%, aptly maximum 0.5%, preferably maximum 0.1% niobium.Nb (C, N) for preparation, also has problems, because can stop up the discharging nozzle (tapping jet) from ladle (ladle) in atomization process.According to described the first embodiment, therefore steel must not contain the niobium more than 6%, preferably contains and is 2.5% to the maximum, is aptly 0.5% niobium to the maximum.In most preferred embodiments, can't stand niobium more than with in the steel process processed from the content of the inevitable impurity of the relict element form of feed metal material.

Except described alloying element, described steel does not need should not contain other alloying elements of any significant quantity yet.Some element does not especially need, because they affect the character of steel in unwanted mode.Be such for phosphorus for example, it should remain on alap level, preferably is 0.03% to the maximum, in order to do not affect the toughness of described steel in disadvantageous mode.In addition, sulphur also is unwanted element in most applications, but its adverse effect for toughness can neutralize by manganese basically, forms basically harmless manganese sulfide, so the tolerable maximum level is that 0.5% sulphur is to improve the machinability of described steel.Titanium, zirconium and aluminium also are unwanted as a rule, but it is added together that can to allow maximum be 7%, but are very low content under normal circumstances, amount to＜0.1%.

As mentioned above, nitrogen content should be adapted to the content of vanadium in the material and the content of the niobium that may exist, take the MX-carbide that gives described steel amount as 5 to 40 volume % ,-nitride and/or-carbonitride.Fig. 1 has shown N and (V+Nb/2) situation of ratio, and it shows for the content of N in the steel of the present invention content with respect to (V+Nb/2).Shown in coordinate with following table of corner point in the zone:

Table 1.N and ratio (V+Nb/2)

?	N	V+Nb/2
			C	8.0	14.0
D	4.3	14.0
			E”	4.8	7.5
E”’	6.5	11.0
			F”	5.8	7.5
F”’	8.0	11.0
			G	9.8	14.0
H	2.6	14.0
			I”	1.6	7.5
I”’	2.1	11.0
			J”	2.6	7.5
J”’	3.5	11.0

The first aspect of used steel according to the present invention, the on the one hand content of N and the on the other hand content of (V+Nb/2), balance relative to each other is so that the content of these elements is by the coordinate I in the coordinate system of Fig. 1 ", F ", G, H, I " in the zone that limits.

According to of the present invention first preferred embodiment, the content of described nitrogen in steel, vanadium and the niobium that may exist is balance relative to each other, so that described content is by coordinate I ", F ", F " ', I " ', I " in the zone that limits, and more preferably at J ", E ", E " ', J " ', J " in the zone that limits.

Table 2 shows the % by weight according to the compositing range of first steel preferred embodiment of the present invention.

Table 2

Element	C	Si	Mn	Cr	Mo	V	N
								Minimum	0.10	0.01	0.01	18.0	0.01	7.5	2.5
Standard	0.20	0.30	0.30	21.0	1.3	9.0	4.3
								Maximum	1.5	1.5	1.5	21.5	2.5	11	6.5

Be applicable to the wear surface of product according to the steel of first embodiment, described surface has the corrosion resistance of high request and high rigidity (up to 60 to 62HRC) and the wearability (abrasive wear/adhesive wear (adhesive)/plucking (galling)/fretting) of ductility and high request preferably.By means of show described composition according to this, described steel has matrix, described matrix is from the sclerosis of the austenitizing temperature of 1080 ° of C and 200 to 450 ° of C lonneals 2x2 hour, or at 450 to 700 ° of C high temperings after 2x2 hour, be comprised of tempered martensite, the amount of the hard phase that described martensite has is comprised of following: up to the M of about 3 to 15 volume % ₂X, wherein M is mainly Cr and V, and X is mainly N, and 15 to 25% MX, and wherein M is mainly V, and X is mainly N.

Table 3 shows the % by weight of the compositing range of the steel of other preferred embodiment according to the present invention.

Table 3

Element	C	Si	Mn	Cr	Mo	V	N
								Minimum	0.10	0.01	0.01	30.0	0.01	7.5	4.0
Standard	0.20	0.30	0.30	32.0	1.3	9.0	5.6
								Maximum	1.5	1.5	1.5	33.0	2.5	11	7.0

In the scope of the inventive concept, also conceivable is to allow nitrogen content up to about 9.8%, itself and the carbon content combination that up to about 14% content of vanadium and scope is 0.1 to 2%, give steel required character, especially for wear surface, described surface has the corrosion resistance of high request and high rigidity (up to 60 to 62HRC) and moderate ductility and the wearability (abrasive wear/adhesive wear/plucking/fretting) of high requirement.The steel of described embodiment has matrix, described matrix is from the sclerosis of the austenitizing temperature of about 1100 ° of C and 200 to 450 ° of C lonneals 2x2 hour, or at 450 to 700 ° of C high temperings after 2x2 hour, be comprised of tempered martensite, the amount of the hard phase that described martensite has is comprised of following: up to the M of about 2 to 15 volume % ₂X, wherein M is mainly Cr and V, and X is mainly N, and 15 to 25% MX, and wherein M is mainly V, and X is mainly N.

The steel of above-mentioned embodiment has proved the pad abrasive disc that is applicable to the bands for band guider, and this pad abrasive disc is exposed to the wearing and tearing of mobile bands for band.Adhesive wear and abrasive wear, particularly plucking and fretting that described pad abrasive disc experience is mixed significantly.

In heat treatment, by austenitizing, described temperature is preferably 1020-1130 ° of C to described pad abrasive disc, most preferably is 1050-1120 ° of C in the temperature of 950-1150 ° of C.Higher austenitizing temperature is acceptable in principle, but because the inadaptable higher temperature of common existing hardening furnace is therefore also improper.The suitable retention time at austenitizing temperature is 10 to 30 minutes.Described steel is cooled to room temperature or lower from described austenitizing temperature, for example is low to moderate-40 ° of C.For eliminating retained austenite to give product required dimensional stability, can carry out cryogenic refrigeration, it carries out in the dry ice of about-70 to-80 ° of C or in the liquid nitrogen of about-196 ° of C aptly.For obtaining best corrosion resistance, at 200 to 300 ° of C with described instrument lonneal at least one times, preferred 2 times.If described steel is through optimizing to obtain post-curing, so in the temperature of 400-560 ° of C, preferably in the temperature of 450 and 525 ° of C with the product high tempering at least one times, preferred 2 times, and may tempering for several times.This product of cooling after each this temper.Preferably, also press in this case the described use cryogenic refrigeration of preamble, may further guarantee required dimensional stability by residual retained austenite by eliminating.Can be 1 to 10 hour in the retention time of temperature, preferred 1 to 2 hour.The composition of wear-resisting steel has given very good tempering response.

Relevant from the different heat treatment of pad abrasive disc experience, for example at high temperature insostatic pressing (HIP) during with the combination product that form to compress, with when the made combination product of sclerosis, carbide, nitride and/or carbonitride contiguous in the wear-resisting steel can merge and form large agglomerate.Therefore the size of hard-phase particles can surpass 3 μ m described in the wearing layer that make, heat treated product.The scope of major part as 1 to the 10 μ m in the longest elongation of particle that represents take volume %, and the average-size of particle is lower than 1 μ m.The total amount of hard phase depends on the amount of nitrogen content and nitride formation (namely being mainly vanadium and chromium).The scope of the total amount of hard phase is 5 to 40 volume % in the wearing layer of the product of usually, making.

The used powdered steel of preparation pad abrasive disc, by disintegration have wear-resisting steel shown in form (except nitrogen) melt prepare.With inert gas, preferred nitrogen is blown over the melt ejecta, and described melt is split into the drop that allow to solidify, and makes subsequently the gained powder carry out the solid phase nitriding to reach required nitrogen content.

The experiment of carrying out

For seek allowing the material of long pad abrasive disc with relatively cheap bands for band guider of preparation life-span, described pad abrasive disc is exposed to the wearing and tearing of mobile bands for band, has carried out following experiment.

At the band saw that is used for the sawing metal, the pad abrasive disc with sintered-carbide piece that is brazed on the support has been adhered to about 6 months, then loses efficacy because breaking.With the steel of steel Vanax 75(powder metallurgy preparation, it has the composition in interval shown in the claim 1) the pad abrasive disc made, still can move after using more than a year, and still keep good shape surprisingly.

Fig. 8 to 10 shows the pad abrasive disc for the bands for band guider of the present invention preferred embodiment, and described pad abrasive disc is exposed to the wearing and tearing of mobile bands for band.As shown in the figure, pad abrasive disc 1 of the present invention can have very simple form, the piece that is essentially parallelepiped that for example Vanax 75 makes, and this makes it to be very easy to and cost prepares effectively.In the embodiment shown, it shows that long 2 the order of magnitude is 10cm, and wide 3 the order of magnitude is 6cm, and thick 4 the order of magnitude is 2cm.Preferably, described pad abrasive disc length is 10cm ± 20%, and width is 6cm ± 20%, and thickness is 2cm ± 20%.Preferably, at least the leading edge of wear surface 5 (leading edge) 9(its be intended to towards bands for band) be rounded.On the described surface 6 towards opposite side two threaded blind bores 7 and 8 are arranged, it allows described pad abrasive disc to be fixed in (also demonstration) on the carrier by the screw (not shown) at an easy rate.

Even shown pad abrasive disc is shown as the solid block of Vanax 75, also might preferably make in some cases its metallurgical binding to the support (not shown) to form combination product.For example, described support can be made than Vanax 75 better materials by heat conductivity, to improve the heat radiation from wear surface.

Steel by the preparation of high temperature insostatic pressing (HIP) body cutting Vanax 75(powder metallurgy, it forms within interval range claimed in claim 1) reference test bar, then with its grinding and polishing, become and the alloy phase that applies by welding surface smoothness (surface finish) together.

The prod of heat treatment Vanax 75 in vacuum drying oven uses nitrogen as hardening media.Used heat treatment cycle is at austenitizing temperature (T _A=1080 ° of C) austenitizing is 30 minutes, then cryogenic refrigeration in liquid nitrogen, and at the temperature tempering twice of 400 ° of C, each 2 hours (2x 2 hours).

Microscopic structure

The microscopic structure of Vanax 75 is comprised of the MX-type hard phase of martensite matrix and 23 volume %, and wherein M is V, and X is N and C.This hard-phase particles average-size is lower than 3 μ m, preferably is lower than 2 μ m, and even more preferably less than 1 μ m.This hard-phase particles is uniformly distributed in the matrix, sees Fig. 4.

Test two Vanax 75 surfaces frictional properties relative to each other, see among Fig. 5.This material has shown the frictional property of good even level, and μ is about 0.36, and this may be owing to even distribution very thin and hard hard-phase particles.

The tempering response

Tested the tempering response of wear-resisting steel Vanax 75.

The result sees among Fig. 7, and proves that described wear-resisting steel have very good tempering response.For the Vanax 75 under the deep frozen condition, obtained 60 to 62HRC hardness up to the tempering of about 500 ° of C.Vanax 75 under the non-deep frozen condition has shown good tempering response and has obtained 51 to 55HRC hardness.

Heat-resisting quantity

The heat-resisting quantity of wear-resisting steel is by research hard-phase particles influenced check how when being heated to the different temperatures of about 1300 ° of C at the most.Can determine that hard-phase particles is very stable.Basically, hard-phase particles is growth or considerably less the growth not, although used high temperature.If material uses in higher operating temperature (700 to 800 ° of C) and with the long operating time, this is very favorable.

Machinability

Detected the machinability of wear-resisting steel of the present invention.Under terms of delivery (delivery condition), namely under quiet soft annealing condition (35HRC) conditions such as heat, and under sclerosis and tempered condition (60HRC), checked the machinability (seeing Fig. 7) of Vanax 75.Vanax 75 under terms of delivery has best machinability (1.0).

Claims

1. prepare the method for the pad abrasive disc of bands for band guider, described pad abrasive disc is exposed to the wearing and tearing of mobile bands for band, it is characterized in that following steps:

– prepares wear-resisting steel in the powder metallurgy mode, and it has following composition, in % by weight:

And, further,

7.5 (V+Nb/2) to 14, the wherein on the one hand content of N and on the other hand the content balance relative to each other of (V+Nb/2), so that the content of described element I in vertical plane coordinate system ", F ", G, H, I " scope in; wherein the content of N is that the content of abscissa and V+Nb/2 is ordinate, and the coordinate of wherein said point is as follows:

? I” F” G H N 1.6 5.8 9.8 2.6 V+Nb/2 7.5 7.5 14.0 14.0

With

Among Ti, Zr and the Al any is 7 to the maximum,

Surplus only is iron and inevitable impurity basically;

– is at 1000 to 1350 ° of C, and preferred 1100 to 1150 ° of C carry out high temperature insostatic pressing (HIP) with the pressure of 100Mpa to prepared powder, and the duration is 3 hours, reaches complete DB or is similar at least complete DB; With

-this DB of heat treatment in the following manner: the austenitizing temperature sclerosis of from 950 to 1150 ° of C and 200 to 450 ° of C lonneal 2x 2 hours, or 450 to 700 ° of C high tempering 2x 2 hours, with the steel pad abrasive disc that preparation has following microscopic structure, this microscopic structure comprises the equally distributed at the most M of 50 volume % ₂X-, MX-and/or M ₂₃C ₆/ M ₇C ₃-type hard-phase particles, described hard-phase particles is of a size of 1 to 10 μ m in its longest elongation, the content of wherein said hard-phase particles so that at the most 20 volume % be M ₂The X-carbide ,-nitride and/or-carbonitride, wherein M is mainly Cr, and X is mainly N, and 5 to 40 volume % be the MX-carbide ,-nitride and/or-carbonitride, wherein M is mainly V and Cr, and X is mainly N, and the average-size of wherein said MX-particle is lower than 3 μ m, preferably be lower than 2 μ m, and even more preferably less than 1 μ m.

2. according to claim 1 method characterized by further comprising:

-with powder packaging in jacket;

Gas in the-discharge jacket; And after high temperature insostatic pressing (HIP),

-remove the jacket that covers wear-resisting steel or at least part of jacket.

3. according to claim 1 and 2 method is characterized in that by the powder particle in the bonded wear-resistant steel powder, and subsequently the powder particle of gained combination is packaged in the jacket, and prepares the intermediate products of wear-resisting steel.

4. according to claim 3 method, wherein said intermediate products have the shape of strip or cushion.

5. it is characterized in that by high temperature insostatic pressing (HIP) combining powder particle according to claim 3 or 4 method.

6. each method in 5 according to claim 2, wherein this jacket wall mainly is comprised of nickel or monel metal.

7. each method in 6 according to claim 1, it is characterized in that with inert gas, preferred nitrogen, has the powder that melt that these wear-resisting steel form shown in except nitrogen prepares wear-resisting steel by disintegration, described inert blowing gas is crossed the melt ejecta, described melt is split into the drop that allow to solidify, and makes subsequently the gained powder carry out the solid phase nitriding to reach indicated nitrogen content.

8. each method in 7 according to claim 1, wherein following element is included in the described pad abrasive disc, and content is with % by weight:

9. each method in 7 according to claim 1 is characterized in that in described wear-resisting steel the content that carbon exists is 0.1 to 2 % by weight, and the content of nitrogen is 9.8 % by weight at the most, and the content of vanadium is about 14 % by weight at the most.

10. the pad abrasive disc of bands for band guider, described pad abrasive disc is exposed to the wearing and tearing of mobile bands for band, it is characterized in that the steel assembly that described pad abrasive disc is following composition:

And, further,

? I” F” G H N 0.6 1.6 9.8 2.6 V+Nb/2 0.5 0.5 14.0 14.0

With

Among Ti, Zr and the Al any is 7 to the maximum,

Surplus only is iron and inevitable impurity basically; And

Described steel pad abrasive disc has following microscopic structure, and this microscopic structure comprises the equally distributed at the most M of 50 volume % ₂X-, MX-and/or M ₂₃C ₆/ M ₇C ₃-type hard-phase particles, described hard-phase particles are of a size of 1 to 10 μ m in its longest elongation, the content of wherein said hard-phase particles so that at the most 20 volume % be M ₂The X-carbide ,-nitride and/or-carbonitride, wherein M is mainly Cr, and X is mainly N, and 5 to 40 volume % be the MX-carbide ,-nitride and/or-carbonitride, wherein M is mainly V and Cr, and X is mainly N, and the average-size of wherein said MX-particle is lower than 3 μ m, preferably be lower than 2 μ m, and even more preferably less than 1 μ m.

11. pad abrasive disc according to claim 10 is characterized in that following element is included in the wear-resisting steel, content is with % by weight:

12. pad abrasive disc according to claim 10 is characterized in that in described wear-resisting steel, the content that carbon exists is 0.1 to 2 % by weight, and the content of nitrogen is 9.8 % by weight at the most, and the content of vanadium is about 14 % by weight at the most.

13. steel prepare purposes in the pad abrasive disc of bands for band guider at powder metallurgy, described pad abrasive disc is exposed to the wearing and tearing of mobile bands for band, it is characterized in that described steel have the composition of following percentage by weight:

And, further,

? I” F” G H N 1.6 5.8 9.8 2.6 V+Nb/2 7.5 7.5 14.0 14.0

And

Among Ti, Zr and the Al any is 7 to the maximum,

Surplus only is iron and inevitable impurity basically; And

Described powdered steel material further so that, at 1000 to 1350 ° of C, preferred 1100 to 1150 ° of C, with the pressure of 100Mpa to prepared powder high temperature insostatic pressing (HIP), duration is 3 hours, reach complete DB or be similar at least complete DB, and the subsequently sclerosis of the austenitizing temperature by from 950 to 1150 ° of C and 200 to 450 ° of C lonneal 2x 2 hours, or 450 to 700 ° of C high tempering 2x 2 hours with after this DB is heat-treated, it has following microscopic structure, and this microscopic structure comprises the equally distributed at the most M of 50 volume % ₂X-, MX-and/or M ₂₃C ₆/ M ₇C ₃The hard-phase particles of type, described hard-phase particles are of a size of 1 to 10 μ m in its longest elongation, the content of wherein said hard-phase particles so that at the most 20 volume % be M ₂The X-carbide ,-nitride and/or-carbonitride, wherein M is mainly Cr, and X is mainly N, and 5 to 40 volume % be the MX-carbide ,-nitride and/or-carbonitride, wherein M is mainly V and Cr, and X is mainly N, and the average-size of wherein said MX-particle is lower than 3 μ m, preferably be lower than 2 μ m, and even more preferably less than 1 μ m.